simpson



2 Sheets Sheet 1.

SIMPSUN APPARATUS POA CASTING METALS.

(No Model.)

ema MAA-"7, 1893.

(No Model.) 2 Sheets-Sheet `2.

. W. S. SIMPSON.

APPARATUS FOR-GASTING METALS. No. 493,047. Patented Mar. '7, 1893..

UNITED STATES PATENT OEEICE.

WILLIAM SPEIRS SIMPSON, OF LONDON, ENGLAND.

APPARATUS FOR CASTINGv METALS.

SPECIFICATION forming part of Letters Patent N o. 493,047, dated March- '7, 1893.

Application filed September 15,1892. Serial No. 445,992. (Nia model.) Patented in England July 20,1892, No.13,298; in France A July 25, 1892, No. 209,991; in Germany July 26, 1892, No. 13,702, and in Belgium July 28.1892, No. 76,207.

y useful Improved Apparatus for Eiecting the Casting of Metals in Vacuo, (patented in Great Britain, No. 13,298, dated July 20, 1892; in France, No. 209,991, dated July 25, 1892; in Belgium, No. 76,207, dated July 28, 1892, and

in Germany, No. 13,702, dated July 26, 1892,).

of which the following is a specification.

Myinventiou relates to an improved method of casting metals undera vacuum, and has for its 4object the production of castings which are sharper and cleaner and are more homogeneous, soft, andductile than those made in the ordinary manner of castingunder atmospheric pressure.

In carrying out my invention, I inclose an ordinary box or flask in which the mold is formed in an air tight chamber in which a vacuum is produced by any suitable means, so that when the metal is poured it lls all the cavities and interstices of the mold undisturbed by the generation ot' any vapor or gas.

In connection with the chamber inclosin g the molding box, I use a subsidiary chamber (air tight) containing a ladle or a cruciblein which is placed the metal previous toits being poured into the mold, a vacuum is formed in this subsidiary chamber, and thus the molten metal is exposed to an exhausting action which has the effect of taking olf all the gases and vapors contained in the fiuid and rendering the metal dead as far as any tendency to ebullition is concerned.

Figures 1 and 2 of the annexed drawings are longitudinal sections of the apparatus. Fig. 3 a transverse section. Fig. 4 a similar section with stirrer.

An ordinary molding box A is placed in the chamber B which has a removable cover C making an air tight joint with the top of the chamber and allowing the molding box to be lplaced in position and removed, this lid has l a hole D in it over the part of the box where the metal is poured, and also two spy'holes E, E, arranged to give a View of the risers in' the molding box. A Isubsidiary chamber F with a movable lid or cover F is arranged .so as to fit over the hole D, and the ladle or crucible G is placed in a suitable cradle or frame H which is hung on a spindle I passing through a stuiting box J in the `side of the chamber F, the end of the spindle I being fitted with a handle or wheel I tocontrol the tilting of theladle.

A plate of metal KA sufficiently strong to resist the pressure of the atmosphere but of a nature to be easily` fused bythe impact of the melted metal is placed between the chamber B and the subsidiary chamber F, andan air tight joint is made at this point by means of packing. rings kept in place by the chamber F. The object of this fusible plate is to separate the two chambers until the metal is poured, so that the lower chamber B can be exhausted by means of the pipe connections L while the subsidiary chamber F is exhausted by meansof a pipe connection M and when any gases cease to be given oft the ladle is tilted over, the metal melts the fusible plate and flows into the molding box and completely lls the mold, the molding box being also in a vacuum.

The interior of the subsidiary chamber is provided with ribs N, N, N, N, which serveto `strengthen it against the pressureof the atmosphere and also to retain the lining in position. The cover-F of the subsidiary chamber-F is secured by bolts or clay and may be loosely hinged for the convenience of turning back. A spy hole is provided on top of the chamber F to enable the progress of the metal to be observed, and this spy hole like theothers is ofcourse air tight. When the process of exhaustionis sufficiently rapid, the fusible plate R may be dispensed with and both the main and subsidiary chambers exhausted at thesame time. v

The lower chamberB may be made to open l on the top, or at the end, or at the side or sides, the most convenient for the class of,

work being molded, and any suitable meansl of exhausting may be used. It is obvious that one or more subsidiary chambers F may be employed in connection with the lower chamber B.

One method I employto stir the molten metal is as followsg-A rod P entering the chamber at the top through a stuling box Q reo and having at the end of the rod inside the crucible or ladle C a knob or bell R. The stirrer is connected to a lever S outside the chamber, the lever being pivoted to an arm 'l cast in the chamberitself. A slot U is made in the lever to enable the striker to move up and down.

The method of working is exactly the same' asy an ordinary hand pump the downward movement of the handle S raising the stirrer P out of the molten metal V in the crncible at the same time of course displacing the metal, on moving the handle or lever up again it causes the stirrer to strike the molten metal, if this be done two or three times it has the eect on the molten metal as though it were being knocked with a hammer .or violently stirred thus imparting a fibrous nature to the molten metal.

What I claim, and desire to secure by Letters Patent, is-

ble diaphragm between the chambers normally separating the same, the independent suction pipe connections to the two chambers whereby each may be exhausted of air and gases independently of the other and the tilting ladle arranged in the subsidiary chamber, substantially1 as described.

2. In combination, the mold chamber, the subsidiary chamber, communicating therewith, the suction pipe connections, the tilting ladle in the subsidiary chamberA with means for operating the same extending through an air tight bearing to the outside, and the vertically reciprocating stirrer extending into the tilting ladle and having an outside connection for operating the same, substantially as described. f

In witness whereof l have hereto signed my name this 28th day of July, 1892.

WILLIAM SPEIRS SIMPSON.

, ln presence of- HENRY GARDNER, CHARLES ALFRED GROSSETETE, Both of 166 Fleet Street, London, England. 

